1. Field of the Invention
The present invention relates generally to a vibration isolator for use in, for example, an ambulance for carrying sick or wounded people and, in particular but not exclusively, to a locking mechanism for such a vibration isolator.
2. Description of the Related Art
A vibration isolator on which a stretcher is to be placed includes a vibration isolating mechanism employing, for example, an electrically-operated air suspension system. This system performs level adjustment according to the load (the weight of a sick or wounded person) and absorbs vibration inputted from a vehicle floor using an air spring, thereby lightening a burden applied to the sick or wounded person on the stretcher.
If the sick or wounded person must have a heart massage or the like, the vibration isolator is locked so as not to operate, thus preventing a force applied to the sick or wounded person from escaping.
Recently, a vibration isolator that employs a magneto-spring to improve the riding comfort has been proposed. The vibration isolator proposed by the applicant of this application is of a construction in which a movable frame is allowed to freely rock in the vertical direction and in the longitudinal direction of the vehicle with respect to the vehicle floor.
Accordingly, a locking device for this kind of vibration isolator is required to suppress both the vertical movement and the longitudinal movement of the movable frame. The use of conventional locking devices may give rise to incomplete locking.